Blood pressure variability and baroreceptor function. Clinical and scientific relevance

The human arterial blood pressure shows not only exogenic alterations, but also spontaneous fluctuations. This blood pressure variability has both sci entific and clinical relevance. A well-known phenomenon is the so-called "w hite coat hypertension" which may severely affect diagnosis and therapy of essential hypertension. Furthermore, several studies have provided evidence that die degree of end-organ damage in hypertensive patients is closely re lated to the circadianblood pressure variability. Therefore, it is tempting to suggest that an optimal antihypertensive treatment should take an impro vement of the blood pressure variability into consideration. Among other mechanisms modulating the arterial blood pressure, the barorefl ex function has to be mentioned. Diseases like chronic renal failure, treat ; ment with drugs like ciclosporine A and also smoking have been shown to r educe the baroreflex sensitivity. As the baroreflex sensitivity mainly reflects interactions between the bloo d pressure variability on the one hand and the heart rate variability on th e other hand, it is not surprising that also a reduced baroreflex function is an independent cardiovascular risk factor.